4.4BSD/usr/src/sys/i386/i386/trap.c
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)trap.c 8.1 (Berkeley) 6/11/93
*/
/*
* 386 Trap and System call handleing
*/
#include <machine/cpu.h>
#include <machine/psl.h>
#include <machine/reg.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/acct.h>
#include <sys/kernel.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <machine/trap.h>
#include <machine/dbg.h>
struct sysent sysent[];
int nsysent;
unsigned rcr2();
extern short cpl;
/*
* trap(frame):
* Exception, fault, and trap interface to BSD kernel. This
* common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed. Note that the
* effect is as if the arguments were passed call by reference.
*/
/*ARGSUSED*/
trap(frame)
struct trapframe frame;
{
register int i;
register struct proc *p = curproc;
u_quad_t sticks;
int ucode, type, code, eva;
extern int cold;
if(cold) goto we_re_toast;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
if (curpcb && curpcb->pcb_onfault && frame.tf_trapno != 0xc) {
copyfault: frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
if (ISPL(frame.tf_cs) == SEL_UPL) {
type |= T_USER;
p->p_md.md_regs = (int *)&frame;
curpcb->pcb_flags |= FM_TRAP; /* used by sendsig */
sticks = p->p_sticks;
}
ucode=0;
eva = rcr2();
code = frame.tf_err;
switch (type) {
default:
we_re_toast:
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
printf("trap type %d code = %x eip = %x cs = %x eflags = %x ",
frame.tf_trapno, frame.tf_err, frame.tf_eip,
frame.tf_cs, frame.tf_eflags);
printf("cr2 %x cpl %x\n", eva, cpl);
type &= ~T_USER;
panic("trap");
/*NOTREACHED*/
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER: /* 386bsd */
case T_PROTFLT|T_USER: /* protection fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
case T_RESADFLT|T_USER: /* reserved addressing fault */
case T_RESOPFLT|T_USER: /* reserved operand fault */
case T_FPOPFLT|T_USER: /* coprocessor operand fault */
ucode = type &~ T_USER;
i = SIGILL;
break;
case T_ASTFLT|T_USER: /* Allow process switch */
case T_ASTFLT:
astoff();
if ((p->p_flag & SOWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~SOWEUPC;
}
goto out;
case T_DNA|T_USER:
#include "npx.h"
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna()) return;
#endif
ucode = FPE_FPU_NP_TRAP;
i = SIGFPE;
break;
case T_BOUND|T_USER:
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_OFLOW|T_USER:
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_DIVIDE|T_USER:
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
case T_ARITHTRAP|T_USER:
ucode = code;
i = SIGFPE;
break;
case T_PAGEFLT: /* allow page faults in kernel mode */
if (code & PGEX_P) goto we_re_toast;
/* fall into */
case T_PAGEFLT|T_USER: /* page fault */
{
register vm_offset_t va;
register struct vmspace *vm = p->p_vmspace;
register vm_map_t map;
int rv;
vm_prot_t ftype;
extern vm_map_t kernel_map;
va = trunc_page((vm_offset_t)eva);
/*
* It is only a kernel address space fault iff:
* 1. (type & T_USER) == 0 and
* 2. pcb_onfault not set or
* 3. pcb_onfault set but supervisor space fault
* The last can occur during an exec() copyin where the
* argument space is lazy-allocated.
*/
if (type == T_PAGEFLT && va >= 0xfe000000)
map = kernel_map;
else
map = &vm->vm_map;
if (code & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
rv = user_page_fault(p, map, va, ftype, type);
if (rv == KERN_SUCCESS) {
if (type == T_PAGEFLT)
return;
goto out;
}
if (type == T_PAGEFLT) {
if (curpcb->pcb_onfault)
goto copyfault;
printf("vm_fault(%x, %x, %x, 0) -> %x\n",
map, va, ftype, rv);
printf(" type %x, code %x\n",
type, code);
goto we_re_toast;
}
i = (rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV;
break;
}
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
frame.tf_eflags &= ~PSL_T;
/* Q: how do we turn it on again? */
return;
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
#include "isa.h"
#if NISA > 0
case T_NMI:
case T_NMI|T_USER:
/* machine/parity/power fail/"kitchen sink" faults */
if(isa_nmi(code) == 0) return;
else goto we_re_toast;
#endif
}
trapsignal(p, i, ucode);
if ((type & T_USER) == 0)
return;
out:
while (i = CURSIG(p))
psig(i);
p->p_pri = p->p_usrpri;
if (want_resched) {
int pl;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
* (since the running process is not on a queue.)
* If that happened after we setrq ourselves but before we
* swtch()'ed, we might not be on the queue indicated by
* our priority.
*/
pl = splclock();
setrq(p);
p->p_stats->p_ru.ru_nivcsw++;
swtch();
splx(pl);
while (i = CURSIG(p))
psig(i);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpri = p->p_pri;
curpcb->pcb_flags &= ~FM_TRAP; /* used by sendsig */
}
/*
* syscall(frame):
* System call request from POSIX system call gate interface to kernel.
* Like trap(), argument is call by reference.
*/
/*ARGSUSED*/
syscall(frame)
volatile struct syscframe frame;
{
register int *locr0 = ((int *)&frame);
register caddr_t params;
register int i;
register struct sysent *callp;
register struct proc *p = curproc;
u_quad_t sticks;
int error, opc;
int args[8], rval[2];
unsigned int code;
#ifdef lint
r0 = 0; r0 = r0; r1 = 0; r1 = r1;
#endif
sticks = p->p_sticks;
if (ISPL(frame.sf_cs) != SEL_UPL)
panic("syscall");
code = frame.sf_eax;
p->p_md.md_regs = (int *)&frame;
curpcb->pcb_flags &= ~FM_TRAP; /* used by sendsig */
params = (caddr_t)frame.sf_esp + sizeof (int) ;
/*
* Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always.
*/
opc = frame.sf_eip - 7;
callp = (code >= nsysent) ? &sysent[63] : &sysent[code];
if (callp == sysent) {
code = fuword(params);
params += sizeof (int);
callp = (code >= nsysent) ? &sysent[63] : &sysent[code];
}
if ((i = callp->sy_narg * sizeof (int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
frame.sf_eax = error;
frame.sf_eflags |= PSL_C; /* carry bit */
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
#endif
goto done;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, &args);
#endif
rval[0] = 0;
rval[1] = frame.sf_edx;
error = (*callp->sy_call)(p, args, rval);
if (error == ERESTART)
frame.sf_eip = opc;
else if (error != EJUSTRETURN) {
if (error) {
frame.sf_eax = error;
frame.sf_eflags |= PSL_C; /* carry bit */
} else {
frame.sf_eax = rval[0];
frame.sf_edx = rval[1];
frame.sf_eflags &= ~PSL_C; /* carry bit */
}
}
/* else if (error == EJUSTRETURN) */
/* nothing to do */
done:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
while (i = CURSIG(p))
psig(i);
p->p_pri = p->p_usrpri;
if (want_resched) {
int pl;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
* (since the running process is not on a queue.)
* If that happened after we setrq ourselves but before we
* swtch()'ed, we might not be on the queue indicated by
* our priority.
*/
pl = splclock();
setrq(p);
p->p_stats->p_ru.ru_nivcsw++;
swtch();
splx(pl);
while (i = CURSIG(p))
psig(i);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.sf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.sf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpri = p->p_pri;
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
}
int
user_page_fault (p, map, addr, ftype, type)
struct proc *p;
vm_map_t map;
caddr_t addr;
vm_prot_t ftype;
int type;
{
struct vmspace *vm;
vm_offset_t va;
int rv;
extern vm_map_t kernel_map;
unsigned nss, v;
vm = p->p_vmspace;
va = trunc_page((vm_offset_t)addr);
/*
* XXX: rude hack to make stack limits "work"
*/
nss = 0;
if ((caddr_t)va >= vm->vm_maxsaddr && map != kernel_map) {
nss = clrnd(btoc(USRSTACK - (unsigned)va));
if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
return (KERN_FAILURE);
}
/* check if page table is mapped, if not, fault it first */
#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
if (!pde_v(va)) {
v = trunc_page(vtopte(va));
if ((rv = vm_fault(map, v, ftype, FALSE)) != KERN_SUCCESS)
return (rv);
/* check if page table fault, increment wiring */
vm_map_pageable(map, v, round_page(v+1), FALSE);
} else
v = 0;
if ((rv = vm_fault(map, va, ftype, FALSE)) != KERN_SUCCESS)
return (rv);
/*
* XXX: continuation of rude stack hack
*/
if (nss > vm->vm_ssize)
vm->vm_ssize = nss;
va = trunc_page(vtopte(va));
/*
* for page table, increment wiring
* as long as not a page table fault as well
*/
if (!v && type != T_PAGEFLT)
vm_map_pageable(map, va, round_page(va+1), FALSE);
return (KERN_SUCCESS);
}
int
user_write_fault (addr)
void *addr;
{
if (user_page_fault (curproc, &curproc->p_vmspace->vm_map,
addr, VM_PROT_READ | VM_PROT_WRITE,
T_PAGEFLT) == KERN_SUCCESS)
return (0);
else
return (EFAULT);
}
int
copyout (from, to, len)
void *from;
void *to;
u_int len;
{
u_int *pte, *pde;
int rest_of_page;
int thistime;
int err;
/* be very careful not to overflow doing this check */
if (to >= (void *)USRSTACK || (void *)USRSTACK - to < len)
return (EFAULT);
pte = (u_int *)vtopte (to);
pde = (u_int *)vtopte (pte);
rest_of_page = PAGE_SIZE - ((int)to & (PAGE_SIZE - 1));
while (1) {
thistime = len;
if (thistime > rest_of_page)
thistime = rest_of_page;
if ((*pde & PG_V) == 0
|| (*pte & (PG_V | PG_UW)) != (PG_V | PG_UW))
if (err = user_write_fault (to))
return (err);
bcopy (from, to, thistime);
len -= thistime;
/*
* Break out as soon as possible in the common case
* that the whole transfer is containted in one page.
*/
if (len == 0)
break;
from += thistime;
to += thistime;
pte++;
pde = (u_int *)vtopte (pte);
rest_of_page = PAGE_SIZE;
}
return (0);
}